[Analysis of the determinants of cost savings in traffic accidents on interurban roads in Spain].

Objective: The increase in traffic accidents depends on multiple factors; it generates an economic and public health problem that must be analyzed jointly by agents involved in road safety. The aim of the work was to quantify the effect of various factors in the cost savings due to traffic accidents on interurban roads in Spain.

Methods: It was analyzed, through a lineal regression with panel data model and in the period 2000-2017, how different factors affected cost savings due to the risk of mortality or injury avoided on Spanish interurban roads.

Results: A 1% increase in traffic volume led to a reduction in costs per MVKT (million vehiclekilometres travelled) of €162.46 referring to the risk of mortality, €115.32 for serious injuries and €10.10 for mild injuries. This increase in unemployment caused a cost reduction of €31.43, €10.76 and €0.98, respectively. The same increase in the investment in replacement implied a reduction of these costs of €11 for any risk. A 1% increase in the ageing index led to an increase in costs of €276.83 in terms of mortality risk and €257.49 in terms of injury. Foreign tourism generated a cost of more than €40 for any risk. A 1% increase in GDP per capita led to an increase in costs of €155.50, €138.09 and €8.21 for defined risks. The points driving license led to an increase in costs of €785.50 per MVKR when referring to mortality risks.

Conclusions: Determining factors for cost savings: motorization rate, unemployment rate and investment in replacement interurban roads. Determining factors that increased costs: expiry of the effect of the penalty - points driving licence, ageing index of the population, increase in GDP or proportion of foreign travelers.